Things are very different in Canada, it would seem.
I have a commercial license. If I had a ticket for 15 over, it would be classified as "reckless driving". That is considered one of the highest risk categories in the "CSA" system (essentially a risk assessment tool used by the USDOT). My ticket would cost 4 times more than the average motorist, AND my employer (if I were working for a motor carrier) would pay an additional fine of 4X more than I paid. So a single 15-over ticket leads to well over $2000 just in ticket fees.
I have a LEO friend who said that is why he would never ticket a CDL driver for a common traffic infraction unless he was a major league jerk.